Roles for the endocannabinoid system in ethanol-motivated behavior.

“Alcohol use disorder represents a significant human health problem that leads to substantial loss of human life and financial cost to society. Currently available treatment options do not adequately address this human health problem, and thus, additional therapies are desperately needed.

The endocannabinoid system has been shown, using animal models, to modulate ethanol-motivated behavior, and it has also been demonstrated that chronic ethanol exposure can have potentially long-lasting effects on the endocannabinoid system.

For example, chronic exposure to ethanol, in either cell culture or preclinical rodent models, causes an increase in endocannabinoid levels that results in down-regulation of the cannabinoid receptor 1 (CB1) and uncoupling of this receptor from downstream G protein signaling pathways.

Using positron emission tomography (PET), similar down-regulation of CB1 has been noted in multiple regions of the brain in human alcoholic patients.

In rodents, treatment with the CB1 inverse agonist SR141716A (Rimonabant), or genetic deletion of CB1 leads to a reduction in voluntary ethanol drinking, ethanol-stimulated dopamine release in the nucleus accumbens, operant self-administration of ethanol, sensitization to the locomotor effects of ethanol, and reinstatement/relapse of ethanol-motivated behavior.

Although the clinical utility of Rimonabant or other antagonists/inverse agonists for CB1 is limited due to negative neuropsychiatric side effects, negative allosteric modulators of CB1 and inhibitors of endocannabinoid catabolism represent therapeutic targets worthy of additional examination.”

Psychological and social sequelae of cannabis and other illicit drug use by young people: a systematic review of longitudinal, general population studies.

“Use of illicit drugs, particularly cannabis, by young people is widespread and is associated with several types of psychological and social harm. These relations might not be causal. Causal relations would suggest that recreational drug use is a substantial public health problem…

All these associations seemed to be explicable in terms of non-causal mechanisms.

Available evidence does not strongly support an important causal relation between cannabis use by young people and psychosocial harm…

The lack of evidence of robust causal relations prevents the attribution of public health detriments to illicit drug use.”

http://www.ncbi.nlm.nih.gov/pubmed/15145631

Medical use of cannabis: an addiction medicine perspective.

“The use of cannabis for medical purposes, evident throughout history, has become a topic of increasing interest. Yet on the present medical evidence, cannabis-based treatments will only be appropriate for a small number of people in specific circumstances. Experience with cannabis as a recreational drug, and with use of psychoactive drugs that are prescribed and abused, should inform harm reduction in the context of medical cannabis.”  http://www.ncbi.nlm.nih.gov/pubmed/26059881

“A safer alternative: Cannabis substitution as harm reduction.”  http://www.ncbi.nlm.nih.gov/pubmed/25919477

Does cannabis affect dopaminergic signaling in the human brain? A systematic review of evidence to date.

“While abnormalities in multiple pathways may lead to schizophrenia, an abnormality in dopamine neurotransmission is considered to be the final common abnormality.

One would thus expect cannabis use to be associated with dopamine signaling alterations.

This is the first systematic review of all studies, both observational as well as experimental, examining the acute as well as chronic effect of cannabis or its main psychoactive ingredient, THC, on the dopamine system in man…

In man, there is as yet little direct evidence to suggest that cannabis use affects acute striatal dopamine release or affects chronic dopamine receptor status in healthy human volunteers. ”

http://www.ncbi.nlm.nih.gov/pubmed/26068702

Combined neuroprotective action of adenosine A1 and cannabinoid CB1 receptors against NMDA-induced excitotoxicity in the hippocampus.

“Both adenosine A1 and cannabinoid CB1 receptors trigger similar transduction pathways and protect against neurotoxic insults at the hippocampus, but their combined neuroprotective potential has not been investigated.

We set forth to assess the combined action of A1 and CB1 receptors against glutamate NMDA receptor-mediated excitotoxicity at the hippocampus…

The results suggest that both CB1 and A1 receptors produce additive cumulative neuroprotection against NMDA-induced excitotoxicity in the hippocampus.”

http://www.ncbi.nlm.nih.gov/pubmed/26065937

Cannabidiol as an Intervention for Addictive Behaviors: A Systematic Review of the Evidence.

“Drug addiction is a chronically relapsing disorder characterized by the compulsive desire to use drugs and a loss of control over consumption.

Cannabidiol (CBD), the second most abundant component of cannabis, is thought to modulate various neuronal circuits involved in drug addiction.

The goal of this systematic review is to summarize the available preclinical and clinical data on the impact of CBD on addictive behaviors.

MEDLINE and PubMed were searched for English and French language articles published before 2015. In all, 14 studies were found, 9 of which were conducted on animals and the remaining 5 on humans.

A limited number of preclinical studies suggest that CBD may have therapeutic properties on opioid, cocaine, and psychostimulant addiction, and some preliminary data suggest that it may be beneficial in cannabis and tobacco addiction in humans.

Further studies are clearly necessary to fully evaluate the potential of CBD as an intervention for addictive disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26056464

“CBD is an exogenous cannabinoid that acts on several neurotransmission systems involved in addiction. Animal studies have shown the possible effects of CBD on opioid and psychostimulant addiction, while human studies presented some preliminary evidence of a beneficial impact of CBD on cannabis and tobacco dependence. CBD has several therapeutic properties on its own that could indirectly be useful in the treatment of addiction disorders, such as its protective effect on stress vulnerability and neurotoxicity… The dreadful burden of substance-use disorder worldwide, combined with the clear need for new medication in the addiction field, justifies the requirement of further studies to evaluate the potential of CBD as a new intervention for addictive behaviors.”  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4444130/

http://www.thctotalhealthcare.com/category/addiction/

Is cannabis use associated with less opioid use among people who inject drugs?

“Clinical, experimental, and ethnographic research suggests that cannabis may be used to help manage pain.

Ethnographic research has revealed that some people are using cannabis to temper their illicit opioid use. We seek to learn if there is an association between cannabis use and the frequency of nonmedical opioid use among people who inject drugs (PWID).

…people who used cannabis used opioids less often than those who did not use cannabis…

There is a statistical association between recent cannabis use and lower frequency of nonmedical opioid use among PWID.

This may suggest that PWID use cannabis to reduce their pain and/or nonmedical use of opioids.”

http://www.ncbi.nlm.nih.gov/pubmed/26051162

Enhancement of endocannabinoid signaling protects against cocaine-induced neurotoxicity.

“Cocaine is an addictive substance with a potential to cause deleterious effects in the brain. The strategies for treating its neurotoxicity, however, are limited.

Evidence suggests that the endocannabinoid system exerts neuroprotective functions against various stimuli. Thus, we hypothesized that inhibition of fatty acid amide hydrolase (FAAH), the main enzyme responsible for terminating the actions of the endocannabinoid anandamide, reduces seizures and cell death in the hippocampus in a model of cocaine intoxication…

In conclusion, the pharmacological facilitation of the anandamide/CB1/PI3K signaling protects the brain against cocaine intoxication in experimental models. This strategy may be further explored in the development of treatments for drug-induced neurotoxicity.”

http://www.ncbi.nlm.nih.gov/pubmed/25933444

Cannabidiol Rescues Acute Hepatic Toxicity and Seizure Induced by Cocaine.

“Cocaine is a commonly abused illicit drug that causes significant morbidity and mortality. The most severe and common complications are seizures, ischemic strokes, myocardial infarction, and acute liver injury. Here, we demonstrated that acute cocaine intoxication promoted seizure along with acute liver damage in mice, with intense inflammatory infiltrate.

Considering the protective role of the endocannabinoid system against cell toxicity, we hypothesized that treatment with an anandamide hydrolysis inhibitor, URB597, or with a phytocannabinoid, cannabidiol (CBD), protects against cocaine toxicity.

URB597 (1.0 mg/kg) abolished cocaine-induced seizure, yet it did not protect against acute liver injury.

Using confocal liver intravital microscopy, we observed that CBD reduced acute liver inflammation and damage induced by cocaine and prevented associated seizure.

Additionally, we showed that previous liver damage induced by another hepatotoxic drug (acetaminophen) increased seizure and lethality induced by cocaine intoxication, linking hepatotoxicity to seizure dynamics.

These findings suggest that activation of cannabinoid system may have protective actions on both liver and brain induced by cocaine, minimizing inflammatory injury promoted by cocaine, supporting its further clinical application in the treatment of cocaine abuse.”

http://www.ncbi.nlm.nih.gov/pubmed/25999668

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4427116/

Use of Prescription Pain Medications Among Medical Cannabis Patients: Comparisons of Pain Levels, Functioning, and Patterns of Alcohol and Other Drug Use.

“Management of chronic pain is one of the most common reasons given by individuals seeking medical cannabis. However, very little information exists about the concurrent use of cannabis and prescription pain medication (PPM).

This study fills this gap in knowledge by systematically comparing medical cannabis users who use or do not use PPM, with an emphasis on understanding whether concurrent use of cannabis and PPM is associated with more serious forms of alcohol and other drug involvement…

PPM users rated the efficacy of cannabis higher than PPM for pain management and indicated a strong desire to reduce PPM usage.

Use of PPM among medical cannabis users was not identified as a correlate for more serious forms of alcohol and other drug involvement.”

http://www.ncbi.nlm.nih.gov/pubmed/25978826